The subject matter disclosed herein relates to communication by voltage modulation and current sensing.
Often, programmable logic controllers (PLCs), distributed control systems (DCSs), and balance of plant (BOPS) communicate using the Highway Addressable Remote Transducer (HART) protocol. As such, the HART protocol is often used in asset management. For example, HART is used in power plants to constantly scan devices and gather operation data. A receiver device communicating on the HART protocol requires the ability to modulate the terminal voltage between two terminals while monitoring the loop current flowing between the terminals. Generally, a HART communication device uses a transformer to impress a voltage while not altering the current. However, using a transformer is not practical for a solid state design such as implemented within an integrated circuit such as an application specific integrated circuit (ASIC). The reliance on such relatively large, discrete components stands in the way of implementing the HART protocol onto a switching block of an ASIC chip.